Take Five #1 - PowerPoint Presentation

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Take Five #1 Slide2

Al(s) + 3AgNO

3

(aq)  Al(NO3)2(aq) + 3Ag(s)1. This equation represents which type of chemical reaction?A Single-replacementB Double-replacementC DecompositionD Synthesis

2. In the formula for barium chloride, (BaCl2), barium (Ba) is written first because it is – A a single atomB a larger atomC the positive ionD the negative ion

Which element will most likely form covalent bonds with fluorine?A CarbonB PotassiumC NeonD TinSlide3

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. The physical process of evaporation involves –

A ion formationB electron sharingC transferring valence electronsD overcoming intermolecular forces5. A substance has molecular formula of C8H10N4O2. The empirical formula is – A C2H6N2O

B C4H5N2OC C9H7N3OD CHNO

6. What is the density of an aqueous solution that has a mass of 10.081 g and 12.5 mL? Your answer must use significant digits.Slide4

Take Five #2 Slide5

1. The most efficient way to determine whether a reaction is an exothermic chemical reaction is to use —

A

an oxygen probeB a temperature probeC a pressure probeD a pH probe2. What is the molarity of a solution with 0.2 moles of potassium permanganate (KMnO4) dissolved in enough water to make a 500.0 mL solution?A 0.0004 MB 0.1 MC 0.4 MD 100 M

3. Which of these is NOT required to ensure that stock solutions are free of contamination?A Store all solutions in brown bottlesB Do not place dropping pipettes in stock solution bottlesC Never return excess chemicals to stock bottlesD Replace tops on reagent bottles after useSlide6

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. Based on the information provided, which solution is a base and a weak electrolyte?

A NaHCO3 B HClOC NaNO3 D CH3NH24. What is the name for FeCl3 using the IUPAC nomenclature rules ?A Iron chlorideB Iron (II) chlorideC Iron trichlorideD

Iron (III) chloride6. An expandable container of oxygen gas has a volume of 125 mL at a temperature of 25.0°C. What volume will the gas occupy at 55.0°C?Slide7

Take Five #3Slide8

1. While English physicist J.J. Thomson was carrying out experiments on cathode rays, he was able to determine that the rays consisted of particles he called “corpuscles”. These particles were later named –

A

protonsB electronsC gamma raysD neutrons2. Which of these correctly describes how organic catalysts operate in biological reactions?A They are used up in the reactions.B They lower the overall energy of the reactions.C They lower the activation energy of the reactions.D They keep the temperature of the reactions constant.Slide9

3. Each of four groups of students determined and recorded the melting point of a solid compound. If the actual melting point is 113°C, which group had the best precision?

A

Group 1B Group 2C Group 3D Group 44. Which structure represents a nonpolar molecule?Slide10

Take Five #4Slide11

1. Using only one trial to collect data in an experiment –

A

makes it easier to determine the a valid conclusionB reduces the percent error in the resultsC causes the conclusion to be less reliableD requires data with more significant figures2. A common product of acid-base neutralization reactions is —A hydrogenB waterC carbon dioxideD oxygen3. What is the half-life of Americium-242?

A 11 hoursB 16 hoursC 32 hoursD 64 hoursSlide12

4. Two electrons are shared equally in bromine (Br

2

). What type of bond is represented between the bromine atoms in this Lewis structure?A Nonpolar covalent bondB Polar covalent bondC Metallic bondD Ionic bondIn the Haber process, nitrogen (N2) and hydrogen (H2) are directly combined to form ammonia (NH3). Which illustration contains the stoichiometric quantities of the reactants for this reaction?Slide13

Take Five #5Slide14

1. Which of these laboratory techniques is best to separate a solid from a liquid to recover the liquid?

A

TitrationB ChromatographyC FilteringD Vaporization2. Which type of chemical reaction does this equation represent?A SynthesisB NeutralizationC Oxidation-reductionD Double-replacement3. Which of the four substances on this pH scale is slightly basic?A

Calcium hydroxideB Human bloodC Whole milkD Lemon juiceSlide15

4. A beaker of water is placed in a large sealed jar that is attached to a vacuum pump. As air is pumped out of the jar, the water begins to boil because –

A

the temperature of the water decreases as the surrounding pressure decreasesB the lower pressure inside the jar causes the water to contractC the air pressure in the jar has been lowered until it is equal to the vapor pressure of the waterD the pressure on the water is insufficient to hold the hydrogen and oxygen atoms together, resulting in a decomposition reaction5. An experiment produced 0.10 g CO2 with a volume of 0.056 L at STP. If the accepted density of CO2 at STP is 1.96 g/L, what is the approximate percent error?A 110% C 71%B 92% D 8.2%Slide16

Take Five #6Slide17

1. A student is studying the effects of several solutions on the prevention of the browning of apples. The student used solutions having different pH values and immersed three apple slices in equal volumes of each of the solutions. Which of these is the independent variable in this investigation?

A

pH of solutionB Shade of brownC Number of apple slicesD Volume of solutions2. Which of these values is most responsible for changing the boiling and freezing points of a solvent?A Molar mass of the solventB Electronegativity of the solventC Weight of the solute particlesD Number of the solute particles3. Calculate the number of moles of Li

3PO4 in 2.2 L of a 0.60 M Li3PO4 solution.Slide18

4. Equilibrium has been reached for the reaction shown. Which conclusion is correct?

A

The N2 and F2 together will form at a faster rate than the NF3.B The partial pressure of N2, F2, and NF3 will stay constant.C The NF3 will form at a faster rate than the N2 and F2 together.D The partial pressure of NF3 will keep changing.

5. If 89.6 joules of heat are needed to heat 20.0 grams of iron from 30.0°C to 40.0°C, what is the specific heat of the iron in ?A 0.448B 2.23C

8.96D 896 6. Increasing the volume of a sealed container will cause the gas particles within the container to – A

form a liquid

B

collide more frequently

C

increase in molecular attraction

D

exhibit lower pressure